/*
 * Copyright 1999-2017 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package studio.raptor.sqlparser.ast.statement;

import java.util.ArrayList;
import java.util.List;
import studio.raptor.sqlparser.ast.SQLExpr;
import studio.raptor.sqlparser.ast.SQLName;
import studio.raptor.sqlparser.ast.SQLStatementImpl;
import studio.raptor.sqlparser.visitor.SQLASTVisitor;

public class SQLUpdateStatement extends SQLStatementImpl {

  protected final List<SQLUpdateSetItem> items = new ArrayList<SQLUpdateSetItem>();
  protected SQLExpr where;
  protected SQLTableSource from;

  protected SQLTableSource tableSource;
  protected List<SQLExpr> returning;

  public SQLUpdateStatement() {

  }

  public SQLUpdateStatement(String dbType) {
    super(dbType);
  }

  public SQLTableSource getTableSource() {
    return tableSource;
  }

  public void setTableSource(SQLTableSource tableSource) {
    if (tableSource != null) {
      tableSource.setParent(this);
    }
    this.tableSource = tableSource;
  }

  public void setTableSource(SQLExpr expr) {
    this.setTableSource(new SQLExprTableSource(expr));
  }

  public SQLName getTableName() {
    if (tableSource instanceof SQLExprTableSource) {
      SQLExprTableSource exprTableSource = (SQLExprTableSource) tableSource;
      return (SQLName) exprTableSource.getExpr();
    }
    return null;
  }

  public SQLExpr getWhere() {
    return where;
  }

  public void setWhere(SQLExpr where) {
    if (where != null) {
      where.setParent(this);
    }
    this.where = where;
  }

  public List<SQLUpdateSetItem> getItems() {
    return items;
  }

  public void addItem(SQLUpdateSetItem item) {
    this.items.add(item);
    item.setParent(this);
  }

  public List<SQLExpr> getReturning() {
    if (returning == null) {
      returning = new ArrayList<SQLExpr>(2);
    }

    return returning;
  }

  public SQLTableSource getFrom() {
    return from;
  }

  public void setFrom(SQLTableSource from) {
    if (from != null) {
      from.setParent(this);
    }
    this.from = from;
  }

  @Override
  public void output(StringBuffer buf) {
    buf.append("UPDATE ");

    this.tableSource.output(buf);

    buf.append(" SET ");
    for (int i = 0, size = items.size(); i < size; ++i) {
      if (i != 0) {
        buf.append(", ");
      }
      items.get(i).output(buf);
    }

    if (this.where != null) {
      buf.append(" WHERE ");
      this.where.output(buf);
    }
  }

  @Override
  protected void accept0(SQLASTVisitor visitor) {
    if (visitor.visit(this)) {
      acceptChild(visitor, tableSource);
      acceptChild(visitor, items);
      acceptChild(visitor, where);
    }
    visitor.endVisit(this);
  }
}
